Explanation:
The Hubble Space Telescope
imaged Pluto and its moon Charon in 1994.
Pluto is usually the most distant planet from the
Sun but because of its elliptic orbit Pluto crossed inside of
Neptune's
orbit in 1979 and will cross back out again in 1999.
Compared to the other planets,
very little is known about Pluto.
Pluto is smaller than any
other planet and even smaller than
several other planet's moons.
From Pluto, the Sun is just a tiny point of light.
Pluto is probably composed of frozen rock and ice,
much like Neptune's moon
Triton. Pluto has not yet been
visited by a spacecraft, but a
mission is being planned for the next decade.